Q 11 :

Energy released when two deuterons $\left({}_1{\mathrm{H}}^2\right)$ fuse to form a helium nucleus $\left({}_2{\mathrm{He}}^4\right)$ is:             

(Given: Binding energy per nucleon of ${}_1{\mathrm{H}}^2=1.1 \text{MeV}$ and binding energy per nucleon of ${}_2{\mathrm{He}}^4=7.0 \text{MeV}$)                [2025]

• 8.1 MeV

   

• 5.9 MeV

   

• 23.6 MeV

   

• 26.8 MeV

   

Q 12 :

The mass of proton, neutron and helium nucleus are respectively 1.0073 u, 1.0087 u and 4.0015 u. The binding energy of helium nucleus is          [2023]

• 14.2 MeV

   

• 28.4 MeV

   

• 56.8 MeV

   

• 7.1 MeV

   

Q 13 :

${}_{92}{}^{238}A\to {}_{90}{}^{234}B+{}_2{}^{4}D+Q$

In the given nuclear reaction, the approximate amount of energy released will be:              [2023]

[Given, mass of ${}_{92}{}^{238}A=238.05079\times 931.5\text{ MeV}/c^2$

mass of ${}_{90}{}^{234}B=234.04363\times 931.5\text{ MeV}/c^2$

mass of ${}_2{}^{4}D=4.00260\times 931.5\text{ MeV}/c^2$]

• 3.82 MeV

   

• 5.9 MeV

   

• 2.12 MeV

   

• 4.25 MeV

   

Q 14 :

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R                   [2023]

Assertion A: The binding energy per nucleon is practically independent of the atomic number for nuclei of mass number in the range 30 to 170.

Reason R: Nuclear force is short ranged.

In the light of the above statements, choose the correct answer from the options given below:

• Both A and R are true but R is NOT the correct explanation of A

   

• A is true but R is false

   

• A is false but R is true

   

• Both A and R are true and R is the correct explanation of A

   

Q 15 :

Nucleus A having Z = 17 and equal number of protons and neutrons has 1.2 MeV binding energy per nucleon. Another nucleus B of Z = 12 has total 26 nucleons and 1.8 MeV binding energy per nucleon. The difference of binding energy of B and A will be ______ MeV.                 [2023]

Q 16 :

If the binding energy of ground state electron in a hydrogen atom is $13.6\text{ eV}$, then, the energy required to remove the electron from the second excited state of ${\mathrm{Li}}^{2+}$ will be: $x\times {10}^{-1}\text{ eV}$. The value of $x$ is _______ .              [2023]

Q 17 :

A nucleus with mass number 242 and binding energy per nucleon as 7.6 MeV breaks into two fragment each with mass number 121. If each fragment nucleus has binding energy per nucleon as 8.1 MeV, the total gain in binding energy is ________ MeV.          [2023]

Q 18 :

A common example of alpha decay is

            ${}_{92}{}^{238}\mathrm{U}\to {}_{90}{}^{234}\mathrm{Th}+{}_2\mathrm{He}^4+Q$

Given:  ${}_{92}{}^{238}\mathrm{U}=238.05060\mathrm{u}$

            ${}_{90}{}^{234}\mathrm{Th}=234.04360\mathrm{u}$

            ${}_2{}^4\mathrm{He}=4.00260\mathrm{u}\text{ and }1\mathrm{u}=931.5\frac{\mathrm{MeV}}{e^2}$

The energy released $\left(Q\right)$ during the alpha decay of ${}_{92}{}^{238}\mathrm{U}$ is ________ MeV.                      [2023]

Q 19 :

Given below are two statements:

Statement I: For all elements, greater the mass of the nucleus, greater is the binding energy per nucleon.

Statement II: For all elements, nuclei with less binding energy per nucleon transform to nuclei with greater binding energy per nucleon.

In the light of the above statements, choose the correct answer from the options given below:                       [2026]

• Statement I is true but Statement II is false

   

• Both Statement I and Statement II are false

   

• Statement I is false but Statement II is true

   

• Both Statement I and Statement II are true

   

Q 20 :

The minimum frequency of photon required to break a particle of mass 15.348 amu into 4 $\alpha$ particles is _______ kHz.

[Mass of He nucleus = 4.002 amu, 1 amu = $1.66\times {10}^{-27}$ kg, $h=6.6\times {10}^{-34}$ J.s and $c=3\times {10}^8$ m/s]             [2026]

• $14.94\times {10}^{19}$

   

• $9\times {10}^{19}$

   

• $9\times {10}^{20}$

   

• $14.94\times {10}^{20}$